Two flower beds are in the form of segments (minor) of the circle circumscribing a square field of side $42 \mathrm{m}$, with two opposite sides of square as the corresponding chords. Find the cost of planting flowers at the rate of $₹200$ per square metre.

On a rectangular window of dimension, $84 \mathrm{cm}\times 56 \mathrm{cm}$, twenty four nonoverlapping circular designs each of radius $7 \mathrm{cm}$ are made at the rate of $₹25 \mathrm{per} 20 {\mathrm{cm}}^2$. Find the cost of making the designs. 

In a round table of diameter $112 \mathrm{cm}$, there is a portion in the form of a regular hexagon inscribed in it. Designs are made on the remaining portion of the table top at the rate of $₹8 \mathrm{per} 15 {\mathrm{cm}}^2$. Find the cost of designing (use $\sqrt{3}=1.73$).​

Find the area of the shaded region in the given figure, having given that $\mathrm{OA}=\mathrm{OB}=28 \mathrm{cm}$

In the given figure $AC=CB=18 \mathrm{cm}$. Find the area of the shaded region using the fact that $OP=\frac{1}{6}AB$.

In the given figure, $O$ is the centre and $AOB$ is the diameter of the circle. Find the area of the shaded region. 

$ABCD$ is a square of side $7 \mathrm{cm}$ and semi-circles are drawn with each side of the square as diameter, thereby forming four similar petals as shown in the adjoining figure. Find the cost of making design on the petals at the rate of $₹12$ per square centimetre.